similar to: calling va_arg functions on win32 seems to require explicit stack alignment?

My code was hinky, but only in the sense that I was accidentally duplicating the definition variable in the module where the function was. With only the declaration in the second module loading the bitcode reproduces the issue. Managed an lli reproduction: $ cat jit-0.ll target datalayout = "e-m:x-p:32:32-i64:64-f80:32-n8:16:32-a:0:32-S32" target triple =

The docs are pretty vague about this. After digging into the examples I got the following to work with JIT to gain a pointer to variable elsewhere in the runtime, but I'd like to understand what is going on here, and if there is a, um, nicer API that I'm missing? llvm::Value* C::getGlobalVariable(const char* name, llvm::Type* t) {

I'm allocating { i8*, i32 } on the stack, and would like to add this as a GC root, but I'm having trouble figuring this out. This works as expected: declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata) define i8* @bar(i8* %x) gc "shadow-stack" { entry: %objptr = alloca i8* call void @llvm.gcroot(i8** %objptr, i8* null) store i8* %x, i8** %objptr %v = load i8*, i8**

Solved by using alloca i8*, i32 2 which the system seems happy enough with, and bitcasting to the actual type for rest of the code after llvm.gcroot. Not entirely sure if this is a terrible workaround or exactly the way gcroot is supposed to be used... On Wed, Nov 1, 2017 at 11:59 AM, Nikodemus Siivola < nikodemus at random-state.net> wrote: > I'm allocating { i8*, i32 } on the

That's useful to know that the static compilation code path works. Furthermore, as expected from that: 52: c7 05 04 00 00 00 d5 00 00 00 movl $213, 4 00000054: IMAGE_REL_I386_DIR32 _foo It looks like the offset `4` of the second field of your struct is correct in the object file, so this does seem to be a problem in the JIT-specific linking/loading.

Hi folk, I'm writing a set of small C code to verify whether my pass handle some instruction correctly. One of the instruction I want to test is "va_arg", but compiling my variadic function does not generate any va_arg instruction. Is va_arg deprecated? Will va_arg instruction ever be generated by any front-end? The source code and llvm instructions are appended as follows. the

Neal, FYI, my group has added a flag to llvm-gcc for emitting the va_arg instruction (instead of lowering in the front-end), and we also have an implementation of the VAARG instruction for X86-64. (which is currently not implemented in the LLVM backend). Both of these things will be sent upstream to LLVM soon, pending some more testing and review. If you are dire need of these features now, I

On 11 June 2017 at 07:53, David Blaikie <dblaikie at gmail.com> wrote: > Sounds like you're looking for reinterpret_cast: http://en. > cppreference.com/w/cpp/language/reinterpret_cast > I tried cast<ConstInt>(vo), but that failed at run-time. > > On Sun, Jun 11, 2017 at 3:06 AM Dipanjan Das via llvm-dev < > llvm-dev at lists.llvm.org> wrote: >

On Mon, Jun 5, 2017 at 1:34 PM, Nikodemus Siivola < nikodemus at random-state.net> wrote: > Uh. Turns out that if I hide the pointer to @foo from LLVM by passing it > through an opaque identity function ... then everything works fine. > > Is this a bug in LLVM or is there some magic involving globals I'm > misunderstanding? > This looks like a bug in the handling of

Hi, I am using llc (llvm 2.9) to generate the MIPS assembly, but failed when compile any codes with va_start()/va_end()/va_arg(). Here is the minimal step to reproduce the failure: llvm-gcc-4.2 -emit-llvm hello.c -c -o hello.bc llc -march=mips hello.bc -o hello.s llc show this erroe message: LLVM ERROR: Cannot select: 0xa1873a0: ch = vaend 0xa187290:1, 0xa185ae0, 0xa187318 [ID=38] 0xa185ae0:

I would like to be able to instrument va_arg, but when I generate a bc file for a test case using: llvm-gcc -O3 -emit-llvm vararg.c -c -o vararg.bc I do not see va_arg. Instead, it seems the args are accessed through %struct.__va_list_tag, which makes things a bit trickier to instrument. Is there a way to force llvm-gcc to use va_arg? Perhaps there is some documentation about va_list_tag or

For the variadic function error with AMD64 abi and windows calling convention on 64bits x86, I find it has been tracked in Bug 20847 (https://llvm.org/bugs/show_bug.cgi?id=20847) (http://reviews.llvm.org/D1622#inline-9345). Do we still plan to fix it? You know, I meet exactly same va_arg mistake with llvm3.7 when I enable the Uefi firmware (http://www.uefi.org/) build with clang. The ms_abi is

i have this code typedef long long L; typedef integer I; void test2(auto L p0, auto L p1, auto L p2, auto L p4, ...) { va_list select; va_start (select, p4); report( va_arg(select,L) ); report( va_arg(select,I) ); report( va_arg(select,L) );

Provide a full-fledged example of working variable arguments on X86_64, since it's easily the most popular platform. Cc: Reid Kleckner <rnk at google.com> Signed-off-by: Ramkumar Ramachandra <artagnon at gmail.com> --- docs/LangRef.rst | 44 ++++++++++++++++++++++++++++++-------------- 1 file changed, 30 insertions(+), 14 deletions(-) diff --git a/docs/LangRef.rst

Hi Richard, Thank you for the info. I build my code in Ubuntu-64bits with simply commands: “clang X64.c”, then run “./a.out” to see the output. If I replace my va_list, va_start, va_arg va_end with __builtin_ms_va_list, __builtin_ms_va_start, __builtin_ms_va_arg, __builtin_ms_va_end, my code will build fail in Ubuntu with below message. Do you suggest I should build it in windows and not in

On Mon, Aug 15, 2011 at 2:18 AM, Leo Chen. <leo.q.chen at gmail.com> wrote: > Hi, > > I am using llc (llvm 2.9) to generate the MIPS assembly I would suggest trying trunk; there have been a lot of improvements recently to the MIPS backend. -Eli > but failed > when compile any codes > with va_start()/va_end()/va_arg(). > > Here is the minimal step to reproduce the

Maybe the easiest workaround would be overriding symbol resolution for the function name and redirect it to your own version in static code (and hope it has no bad side effect on your use case). I think when running 3rd party code, the only way to definitely avoid this kind of trouble is to never deallocate any code or data sections. Doug Binks mentioned that too in his cppcast about Runtime

Since the getelementptrs were implicitly generated by the CreateStore/Load I'm not sure how to get access to them. So I hacked the assignment to be done thrice: once using a manual decomposition into two GEPs and stores, once using the "big" CreateStore, once via the setGlobal function, printing addresses and memory contents at each point to the degree that I have access to them.

Hi everyone, I'm interested in variadic functions and how llvm handles them. I discovered that the Clang frontend is doing a great job at lowering the va_arg (precisely __builtin_va_arg) function into target dependent code. I have also seen the va_arg function that exist at IR level. I found some information about va_arg (IR one) that currently does not support all platform. But since 2009,

For values above integer accuracy in floats, val - floor(val) might actually produce a value greater than 1. For such large floats, it's reasonable to be imprecise, but it's unreasonable for FRC to return a value that is not between 0 and 1. Signed-off-by: Ilia Mirkin <imirkin at alum.mit.edu> --- src/gallium/drivers/nouveau/codegen/nv50_ir_from_tgsi.cpp | 3 ++- 1 file changed, 2